Sample Holder, Ion Milling Apparatus, Sample Processing Method, Sample Observing Method, and Sample Processing and Observing Method

ABSTRACT

The present invention is directed to a side entry type sample holder which enables observation with an observation apparatus without removing the sample to be analyzed from the sample holder after processing the sample to be analyzed by a processing apparatus. The sample holder includes a grip, a sample holder main body extending from the grip, a tip portion which is connected to the sample holder main body and provided with a sample table for fixing a sample, and a mechanism which changes a relative positional relationship between a processing surface of the sample fixed to the sample table and an irradiation direction of an ion beam, and causes the tip portion to avoid irradiation with the ion beam during sample processing.

TECHNICAL FIELD

The present invention relates to a sample holder, an ion millingapparatus, a sample processing method, a sample observing method, and asample processing and observing method.

BACKGROUND ART

An ion milling apparatus is an apparatus which scrapes a sample smoothlywithout stress using a physical sputtering phenomenon in which ions suchas argon generated in an anode are accelerated to approximately 10 kV orless (in order to reduce damage of a sample) and the sample isirradiated with the ions without being focused to flip sample atoms froma sample surface.

A scrapped amount when irradiating the sample with an ion beam dependson a composition of the sample, an irradiation angle of the ion beam, acrystal orientation, and acceleration voltage of the ion beam, and thelike; however, when the sample is set such that the irradiation angle ofthe ion beam is 90 degrees, a variation in the scrapped amount due tothe sample composition can be reduced and multilayer films havingmulti-compositions can also be processed smoothly. At this time, inorder to prevent a position other than an ion milling target positionfrom being irradiated with the ion beam, when irradiating the samplewith the ion beam, a plate (hereinafter, also referred to as a shieldingplate or a mask) is disposed to shield the sample at a processing targetposition from the ion beam in an ion beam irradiation direction (note:meaning of ion source side=ion gun side). Several hundred microns orless of the sample is exposed from the shielding plate to be irradiatedwith the ion beam, and the exposed sample portion can be scraped byphysical sputtering to obtain a smooth sample surface.

In addition, a side entry type sample holder on which a sample to beanalyzed is placed may be adopted for the ion milling apparatus (see PTL1).

CITATION LIST Patent Literature

PTL 1: JP-A-11-258130

SUMMARY OF INVENTION Technical Problem

In a case of using the ion milling apparatus that processes the sampleby using the side entry type sample holder of the related art asdisclosed in PTL 1, the sample to be analyzed is fixed to the side entrytype sample holder to perform milling processing by inserting the holderinto the ion milling apparatus. In this case, the processing surface ofthe sample becomes parallel to the ion beam used for irradiation.

On the other hand, in a case of observing the processing surface of thesample with an electron microscope (for example, SEM or the like), itwas required to coincide the processing surface of the sample with theirradiation direction of an electron beam. Therefore, it was required toextract the side entry type sample holder from the ion milling apparatusand temporally remove the sample, and then fix the sample to the holderof the electron microscope again such that the processing surface andthe observation direction coincided with each other. When undergoingsuch a procedure, as a result, there are problems that an operationbecomes complicated and the sample may be damaged.

The present invention has been made in view of the above circumstances,and proposes a side entry type sample holder which enables observationwith an observation apparatus without removing the sample to be analyzedfrom the sample holder after processing the sample to be analyzed by aprocessing apparatus.

Solution to Problem

In order to solve the problems, the present invention provides a sampleholder which is inserted into an ion milling apparatus so as totransverse an irradiation locus of an ion beam and is extracted from theion milling apparatus after sample processing, the sample holderincluding: a grip; a sample holder main body extending from the grip; atip portion which is connected to the sample holder main body andprovided with a sample table for fixing a sample; and a mechanism whichchanges a relative positional relationship between a processing surfaceof the sample fixed to the sample table and an irradiation direction ofthe ion beam, and causes the tip portion to avoid irradiation with theion beam during sample processing.

Further features relating to the present invention will become apparentfrom the description of the present specification and the accompanyingdrawings. In addition, aspects of the present invention are achieved andrealized according to an element, a combination of elements, thefollowing detailed description, and accompanying claims.

It should be understood that the description of the presentspecification is a merely general example and is not intended to limitthe scope or application example of the present invention in any way.

Advantageous Effects of Invention

According to the present invention, in a state of attaching a sample toa side entry type sample holder, milling processing by a millingapparatus and observation by an observation apparatus can be compatiblewith each other, without removing the sample.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view illustrating a schematic configuration of an ionmilling apparatus 1 according to the present embodiment.

FIG. 2 is a view illustrating an external configuration of a peripheralportion of a tip portion 32 of a side entry type sample holder 30according to the present embodiment.

FIG. 3 is a view illustrating a configuration (side surface) of a sideentry type sample holder according to the present embodiment.

FIG. 4 is a view illustrating a configuration of a tip portion rotationmechanism provided in the side entry type sample holder 30 according tothe present embodiment.

FIG. 5 is a view illustrating an aspect when a sample is processed byusing the side entry type sample holder 30 according to the presentembodiment.

FIG. 6 is a view illustrating an aspect when a processing surface (aprocessed surface) of the sample by using the side entry type sampleholder 30 according to the present embodiment.

FIG. 7 is a flowchart for describing a procedure of processing andobserving the sample according to the present embodiment.

FIG. 8 is a flowchart for describing a procedure of processing andobserving the sample according to a comparative example (related artexample).

FIG. 9 is a view illustrating an example of an external configuration ofa side entry type sample holder 900 according to a second embodiment.

FIG. 10 is a sectional view of the side entry type sample holder 900 ona plane 903 of FIG. 9.

FIG. 11 is a view illustrating an aspect in which the tip portion 32 iscompletely exposed and the tip portion 32 is rotated about a rotationshaft 33 as a center to be in a vertical state.

FIG. 12 is a view illustrating an aspect in which the side entry typesample holder 30 is attached to an observation apparatus (notillustrated) to observe a processing surface 603.

DESCRIPTION OF EMBODIMENTS

A side entry type sample holder according to the present embodimentincludes a grip, a sample holder main body extending from the grip, atip portion which is connected to the sample holder main body andprovided with a sample table for fixing a sample, and a mechanism whichchanges a relative positional relationship of the sample fixed to thesample table with an irradiation direction of the ion beam, and causesthe tip portion to avoid irradiation with the ion beam during the sampleprocessing. During sample processing, since the tip portion of thesample holder moves to a position at which an irradiation with the ionbeam can be avoided (takes a refuge state), the tip portion can beprevented from being damaged due to exposure to the ion beam.

Specifically, the mechanism rotates the tip portion toward a directionopposite to a direction in which the ion source of an ion millingapparatus has been provided, from a state where the tip portion ishorizontal to the sample holder main body.

Further specifically, the mechanism includes a first shaft that ishoused inside the sample holder main body, extends in a direction fromthe connecting portion to the grip, and has a first gear and a secondshaft that has the same axis as the rotation shaft of the tip portionand has a second gear. Then, an operation is performed in such a mannerthat when a rotational force for rotating the first shaft is appliedaround an axis of the first shaft, the rotational force is transmittedto the second gear via the first gear to rotate the second shaft.Accordingly, the tip portion rotates so as to be away from the ionsource and transits to a state where the tip portion becomesperpendicular to the sample holder main body, from a state of beinghorizontal to the sample holder main body.

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. In the accompanying drawings,the same functional elements may be represented by the same numerals.The accompanying drawings show specific embodiments and implementationsin accordance with the principle of the present invention, but these arefor understanding the present invention and are not used to interpretthe present invention in a limited way.

In the present embodiment, the descriptions are made in sufficientdetail to implement the present invention by those skilled in the art,but it should be understood that other implementations andconfigurations are possible and, without departing from the scope andspirit of the technical idea, modifying a configuration or a structureand replacing various elements are possible. Accordingly, the followingdescription should not be interpreted by being limited thereto.

(1) First Embodiment

<Ion Milling Apparatus>

FIG. 1 is a view illustrating a schematic configuration of an ionmilling apparatus 1 according to the present embodiment. The ion millingapparatus 1 includes a sample chamber 10, a stage 20, a side entry typesample holder 30, a motor 40, a control unit 50, and an ion gun 60.

The ion gun 60 irradiates a target (sample) with an unfocused ion beamto process the sample.

An inside of the sample chamber 10 can be evacuated by using a vacuumevacuation device (not illustrated). In addition, the sample chamber 10is provided with a flare prevention diaphragm 11. When processing thesample, irradiation is performed with the ion beam not focused.Therefore, the flare prevention diaphragm is for preventing a part otherthan a sample placed on the side entry type sample holder 30 and theshielding plate (see FIG. 2) from being irradiated with a diffused ionbeam.

The stage 20 is configured so that the side entry type sample holder 30can be attached to the sample chamber 10 without releasing the vacuum ofthe sample chamber 10. In addition, the stage 20 is configured so thatthe side entry type sample holder 30 can be extracted from the samplechamber 10 without breaking the vacuum of the sample chamber 10.

The stage 20 is provided with a stage side gear 21 and is configured sothat the stage side gear 21 meshes with a motor side gear 41 of themotor 40. Then, when the motor rotates, the rotational force thereof istransmitted to the stage side gear 21 via the motor side gear 41 torotate the rotation base 22 of the stage 20. Hereinafter, the motor 40,a motor side gear 41, and the stage side gear 21 are collectivelyreferred to as a “swing mechanism”.

Since the rotation base 22 is in close contact with the side entry typesample holder 30, when the rotation base 22 rotates, the side entry typesample holder 30 also rotates about the rotation shaft 31 (rotates bypredetermined angles respectively in a direction clockwise andcounterclockwise) according to the rotation. A rotation speed and arotation angle of the motor 40 are controlled by the control unit(control unit: for example, a computer) 50. The rotation is alsoreferred to as a swing. According to the rotation, the irradiation angleof the ion beam with which the ion gun 60 performs irradiation can bechanged to obtain an effect of preventing streaks from being formed onthe processing surface of the sample. The rotation angle (swing angle) θis set to, for example, approximately −40 degrees≤θ≤approximately +40degrees. The an input device or a display device (not illustrated) isconnected to the control unit 50 and an operator can instruct therotation amount (swing amount) or a speed of the side entry type sampleholder 30 using the input device. The motor 40 and the control unit 50for driving the motor 40 may not be integrated with the stage 20.

In the side entry type sample holder 30, by rotating a knob 36, the tipportion (pivot) 32 is configured so that a horizontal state can bechanged to a vertical state about a rotation shaft 33 as the center (therotation mechanism will be described later). For example, in a casewhere the tip portion is in the horizontal state, when the knob 36 isrotated clockwise, the tip portion 32 becomes in the vertical state (astate in FIG. 1). On the contrary, when the tip portion is in thevertical state, if the knob 36 is rotated counterclockwise, the tipportion 32 returns to the horizontal state. When the side entry typesample holder is inserted into the stage 20, the tip portion 32 is keptin the horizontal state, and after insertion, the tip portion 32 ischanged to the vertical state as shown in the drawing during sampleprocessing. Then, the irradiation is performed with the ion beam and thesample placed on an end of the side entry type sample holder(specifically, near the rotation shaft 33) is processed with the ionbeam via the flare prevention diaphragm 11.

<External Configuration of Tip Portion of Side Entry Type Sample Holder>

FIG. 2 is a view illustrating an external configuration of a peripheralportion of the tip portion 32 of the side entry type sample holder 30according to the present embodiment. FIG. 2(a) illustrates a state(horizontal state) when the side entry type sample holder 30 is insertedinto or extracted from the stage 20. In addition, FIG. 2(b) illustratesa state (vertical state) when the sample placed on the side entry typesample holder 30 is processed by the ion beam.

In the vicinity of the rotation axis 33 of the tip portion 32, a sampletable 204 is provided (fixed), and a sample 203 is placed on the sampletable 204. In addition, a shielding plate 202 is attached to an uppersurface of the sample 203. A side surface of the sample 203 protrudesslightly (for example, by the amount (of milling) to be processed) fromthe shielding plate 202 and the sample table 204.

As shown in FIG. 2(a), in a case where the tip portion 32 is in thehorizontal state, a side surface portion 2041 of the sample table 204and a processing surface (processing target surface) 206 of the sampleface an ion beam irradiation direction 200.

On the other hand, as shown in FIG. 2(b), when processing the sample203, the tip portion 32 is rotated about the rotation axis 33 as thecenter to change the state to the vertical state. Since the sample table204 is fixed to the tip portion 32, the stage of the sample table 204 isalso changed as the same along with the change of the state of the tipportion 32. When the tip portion is in the horizontal state, the sidesurface portion 2041 of the sample table 204 faces the ion beamirradiation direction 200, but when the tip portion 32 is changed to thevertical state, the side surface portion 2041 becomes in a stateparallel with the ion beam irradiation direction 200. Since the sampleis sandwiched between the sample table 204 and the shielding plate 202,the state of the sample is also changed. In other words, the processingsurface 206 of the specimen 203 becomes in a state of parallel with theion beam irradiation direction 200, from a state of vertical thereto.

In the side entry type sample holder 30, a unit for adjusting a positionof the shielding plate 202 by precision micromanipulator such as aone-or-more directions (axes) micrometer or the like may be provided.

<Configuration of Side Entry Type Sample Holder (Side Surface)>

FIG. 3 is a view illustrating a configuration (side surface) of a sideentry type sample holder according to the present embodiment. FIG. 3(a)illustrates an aspect of a state (horizontal state) when the tip portion32 is not rotated. FIG. 3(b) illustrates an aspect of a state (verticalstate) when the tip portion 32 is rotated.

The side entry type sample holder 30 includes a grip 34, a sample holdermain body 35 extending from the grip 34, the tip portion 32 which isconnected to the sample holder main body and provided with the sampletable 204 for fixing a sample.

A shaft 301 is connected to the knob 36, and the shaft 301 extends froman inside of the side entry type sample holder 30 to the vicinity of therotation shaft 33.

When the knob 36 is rotated, for example, in a clockwise direction 302,the shaft 301 also rotates in the clockwise direction 302. The tipportion 32 is folded in a downward direction 303 about the rotationshaft 33 as the center by the tip portion rotation mechanism (which willbe described later using FIG. 4) to be the vertical state (FIG. 3(b)).

The tip portion 32 is irradiated at the time of rotated state (verticalstate) with the ion beam and the sample 203 placed on the sample table204 is processed. During processing the sample 203, the tip portion 32faces the downward direction 303. Therefore, the tip portion is notexposed to the ion beam and the damage to the tip portion 32 can beprevented.

When the knob 36 is rotated in a counterclockwise direction 305 afterthe processing of the sample 203 is completed, the shaft 301 alsosimilarly rotates in the counterclockwise direction 305. Then, the tipportion rises in an upward direction 306 about the rotation shaft 33 asthe center by the tip portion 32 rotation mechanism described later toreturn to the horizontal state (FIG. 3(a)).

When the sample 203 is placed (fixed) on the sample table 204 and thetip portion 32 is in the horizontal state, a height of the upper tipportion (processing target surface 206) of the sample 203 is lower thanthe height of the uppermost portion of the sample holder main body 305.Accordingly, even when the side entry type sample holder 30 is subjectedto an inserting and extracting operation with respect to the stage 20,the sample 203, the sample table 204, and the shielding 202 do notinterfere with the inserting and extracting operation.

<Tip Portion Rotation Mechanism>

FIG. 4 is a view illustrating a configuration of the tip portionrotation mechanism provided in the side entry type sample holder 30according to the present embodiment. FIG. 4(a) is a top view of the sideentry type sample holder 30. FIG. 4(b) illustrates a configuration of amain part of the tip portion rotation mechanism.

As shown in FIG. 4(a), the shaft 301 extends from the knob 36 to thevicinity of the rotation shaft 33. In addition, a shaft 402 is providedon a portion of the rotation shaft 33 so as to traverse a side surfaceof the side entry type sample holder 30. That is, the center of theshaft 401 coincides with the center of the rotation shaft 33. Then, byrotating the shaft 401, the state of the tip portion 32 transitionsbetween the horizontal state and the vertical state. The rotation of theshaft 401 is realized by rotating the shaft 301. The mechanismillustrated in FIG. 4(b) realizes such an operation.

As shown in FIG. 4(b), a bevel gear 402 is attached to an end of theshaft 301. In addition, a bevel gear 403 meshing with the bevel gear 402is also attached to the shaft 401. When the shaft 301 is rotatedclockwise by the knob 36, the bevel gear 402 provided on the tip portionof the shaft 301 also rotates clockwise. Then, the bevel gear 403meshing with the bevel gear 402 rotates in a direction of an arrow 404,according to this, the shaft 401 also rotates in the direction of thearrow 404. According to such an operation, the tip portion 32 isdisplaced from the horizontal state to the vertical state. If the knob36 is rotated counterclockwise, according to an opposite operation, thetip portion 32 returns to the horizontal state from the vertical state.

<Aspect when Sample Processing>

FIG. 5 is a view illustrating an aspect when a sample 203 is processedby using the side entry type sample holder 30 according to the presentembodiment. Substantially, the flare prevention diaphragm 11 thatregulates an irradiation size of an ion beam 501 is provided above theshield plate 202.

During processing, the tip portion 32 of the side entry type sampleholder 30 becomes to the vertical state, that is, to be parallel to anion beam irradiation direction. The processing surface (processingtarget surface) 206 of the sample 203 also becomes parallel to the ionbeam irradiation direction. In this state, when a projected portion ofthe sample 203 is irradiated with the ion beam 501, the projectedportion of the sample 203 is scraped (the shielding plate 202 may bescraped together in some cases) and the processing surface is exposed.In addition, during processing, the side entry type sample holder 30 isrotated (swung) around the rotation shaft 31 by a predetermined angle bythe swing mechanism described above (see FIG. 1), whereby the sample 203can be swung at the same time. Accordingly, it is possible to preventstripes from being formed on the processing surface of the sample 203,by the ion beam 501. In addition, since the tip portion 32 can beretracted downward during processing, the tip portion 32 can beprevented from being irradiated with the ion beam 501. Accordingly, itis possible to avoid a situation that the tip portion 32 is damaged bybeing scraped by the ion beam 501.

<Aspect when Observing Processing Surface of Sample>

FIG. 6 is a view illustrating an aspect when a processing surface (aprocessed surface) of the sample by using the side entry type sampleholder 30 according to the present embodiment.

After processing the sample, the tip portion 32 of the side entry typesample holder 30 is set to the horizontal state to be extracted from thestage 20 of the ion milling apparatus 1, and attached to an electronmicroscope apparatus (the entire apparatus is not illustrated). In thisstate, a processing surface (a processed surface) 603 of the sample 203faces an electron gun 601. Therefore, the processing surface 603 can beobserved by being irradiated with an electron beam 602 as it is.

Accordingly, it is not required to remove the sample 203 from the sideentry type sample holder 30 and attach the sample again by changing adirection and it is possible to perform an ion milling processing and anSEM observation using the same holder.

Here, an electron microscope is used as an example of the observationapparatus, but the processing surface 603 may be observed using anotherobservation apparatus.

<Procedure of Processing and Observing Sample>

(i) Case of Present Embodiment

FIG. 7 is a flowchart for describing a procedure of processing andobserving the sample according to the present embodiment.

(i-1) Step 701

An operator pretreats the sample. Specifically, the sample is cut intoan appropriate size (for example, a size of approximately 5 mm×5 mm). Ifthe cut surface has unevenness, the surface is treated as even aspossible.

(i-2) Step 702

The operator places the pretreated sample 203 on the sample table 204(side entry sample table for sectional observation) of the side entrytype sample holder 30. Then the operator covers an upper side of thesample 203 with the shielding plate 202, and fixes the sample 203 andthe shielding plate 202 to the sample table 204. At this time, an endportion of the sample is caused to be slightly projected from the samplestage 204 and the shielding plate 202. The amount to be projected isapproximately equal to the amount to be removed by the ion milling.Since a position of the sample is uniquely determined when using theside entry type sample holder 30 according to the present embodiment, itis not required to adjust a sample processing position.

When the sample 203 is placed on the sample table 204, the operatorinserts the side entry type sample holder 30 into the stage 20.

(i-3) Step 703

The operator changes the state of the tip portion 32 of the side entrytype sample holder 30 to the vertical state from the horizontal (seeFIG. 2). Then, a section ion milling processing is performed inside thesample chamber 10 of the ion milling apparatus 1. During processing, theside entry type sample holder 30 is controlled to rotate about the shaft31 as the center clockwise and counterclockwise by predetermined angleby the swing mechanism described above, thereby preventing streaks frombeing formed on the processing surface (processing target surface) 206.

When the processing ends, the stated of the tip portion 32 is changed tothe horizontal state from the vertical state, and the side entry typesample holder 30 is extracted from the stage 20.

(i-4) Step 704

The operator inserts the side entry type sample holder 30, on which theprocessed sample is placed, into the observation apparatus (electronmicroscope apparatus). In this case, the tip portion 32 is kept in thehorizontal state, and the processing surface (a processed surface) 603is caused to face the electron gun 601 (so that the electron beam 602and the processing surface 603 are substantially vertical), theprocessing surface 603 is irradiated with the electron beam 602, and thestate of the processing surface 603 is observed.

(i-5) Step 705

When it is determined that a desired result has been obtained byobserving the processing surface 603, the operator ends the process.

In a case where the desired observation result has not been obtained,the operator extracts the side entry type sample holder 30 from theobservation apparatus, inserts the side entry type sample holder 30 intothe stage 20 of the ion milling apparatus 1 again to perform the ionmilling processing and observation. The operator repeats the aboveprocessing and observation until the desired observation result isobtained.

(ii) Case of Comparative Example (Related Art)

FIG. 8 is a flowchart for describing a procedure of processing andobserving the sample according to a comparative example (related artexample).

(ii-1) Step 801

The operator pretreats the sample. Specifically, the sample is cut intoan appropriate size (for example, a size of approximately 5 mm×5 mm). Ifthe cut surface has unevenness, the surface is treated as even aspossible.

(ii-2) Step 802

The operator fixes the pretreated sample to the sample table for sectionmilling.

(ii-3) Step 803

The operator adjusts the position of the sample so that a predeterminedposition of the sample is irradiated with the ion beam, using aprocessing position adjustment mechanism (XY axis position adjustment)provided on the sample table.

(ii-4) Step 804

The operator performs the section ion milling processing inside thesample chamber of the ion milling apparatus.

(ii-5) Step 805

The operator removes the processed sample from the sample table forsection milling.

(ii-6) Step 806

The operator fixes the sample removed in Step 805 to the sample table ofthe side entry type sample holder for sectional observation to insertthe holder to the observation apparatus (electron microscope).

(ii-7) Step 807

The operator observes the processing surface of the sample with theobservation apparatus.

(ii-8) Step 808

When it is determined that a desired result has been obtained byobserving the processing surface, the operator ends the process.

(ii-9) Step 809

In a case where the desired observation result has not been obtained inStep 808, the operator extracts the side entry type sample holder forsectional observation from the observation apparatus and removes thesample from the sample table of the holder.

The operator repeats operations of the processing and observation fromSteps 802 to 808 until the desired observation result is obtained.

(iii) Advantage of Present Embodiment

As described above, in the procedures of the processing and observationaccording to the present embodiment, man-hours are less than those ofthe comparative example. In particular, in a case of the presentembodiment, it is not required to repeat removal and attachment of thesample between the sample holder for processing and the sample holderfor observation, and throughput can be improved. The attachment andremoval of the sample is a work which should be performed carefullysince there is concern of damaging the sample, which is a time-consumingwork. In addition, in the present embodiment, since the positionadjustment is not necessary when performing the sectional milling (Step803 of the comparative example is not necessary), the procedure at thetime of processing is not complicated, and the sample holder isconvenient for the operator.

(2) Second Embodiment

A second embodiment relates to a side entry type sample holder includinga cap cover which is provided on the tip portion 32 and is for sealing(protecting) the sample 203 (including before and after processing)attached to the sample table 204. A point different from theconfiguration of the first embodiment is that the cap cover for sealing(protecting) the sample 203 attached to the tip portion 32 is added.

FIG. 9 is a view illustrating an example of an external configuration ofa side entry type sample holder 900 according to the second embodiment.FIG. 10 is a sectional view of the side entry type sample holder 900 ona plane 903 of FIG. 9. FIG. 10A illustrates a state where the cap covercompletely covers the tip portion 32. FIG. 10B illustrates a viewillustrating a middle state of moving the cap cover until the sample 203is exposed.

As shown in FIG. 9, the side entry type sample holder 900 includes capbases 901 formed by, for example, a circular plate (which may also be anelliptic plate) and a cap movable portion 902 formed by, for example, acylinder (which may also adopt a pipe shape other than a cylindricalshape), in the vicinity of a position of the tip portion 32 on which thesample 203 is placed. As shown in FIG. 10, each cap base 901 is fixed tothe tip portion 32 and the holder main body 35. Since the cap movableportion 902 is formed as the cylinder, it is possible to operate so asto seal a space inside the cap base 901. For example, an operationmechanism of the cap movable portion 902 may be a type of sliding in aplane perpendicular to the irradiation direction of the electron beam602, and may be a type of rotating along a rotation axis by providingthe rotation axis. An operation method of the cap movable portion 902may be, for example, a method of moving automatically by providing amotor or the like, and also be a method of performing an operation fromthe outside of the sample chamber 10 by providing a rotationintroduction device or the like on the side entry type sample holder 30.In addition, a manipulator or the like may be provided to a tip of theholder to perform operation by the manipulator. Further, variousoperation mechanisms and operation methods can be adopted.

FIG. 11 is a view illustrating an aspect in which the tip portion 32 iscompletely exposed and the tip portion 32 is rotated about a rotationshaft 33 as the center to be in a vertical state. The tip portion 32 canbe folded in the downward direction 303 about the rotation shaft 33 asthe center using the tip portion rotation mechanism as illustrated inthe first embodiment so as to be in the vertical state. In this manner,the tip portion is set to the vertical state, whereby the placed sample203 can be processed with the ion beam 501. Since the cap movableportion 902 is in a completely retracted state (a state where the sample203 is exposed in the space of the sample chamber), the tip portion 32and the cap movable portion 902 do not interfere with each other. Afterprocessing the sample 203, the tip portion 32 returns to an originalposition thereof (from the vertical state to the horizontal state).Next, by operating the operation mechanism described above, the operator(user) moves the cap movable portion 902 in an arrow X1 direction untilthe cap movable portion 902 completely covers the sample 203 (which hasbeen processed) placed on the sample table 204 of the tip portion.Thereafter, the operator extracts the side entry type sample holder 30from the sample chamber 10 (see FIG. 1) and attaches the side entry typesample holder 30 to an observation apparatus (not illustrated).Accordingly, it is possible to observe the ion beam 603 of the sample203. The cap base 901 is desirably made of a material that is difficultto be scraped off by the ion beam 501.

FIG. 12 is a view illustrating an aspect in which the side entry typesample holder 30 is attached to an observation apparatus (notillustrated) to observe the processing surface 603. First, the sideentry type sample holder 30 taken out from the sample chamber 10 of theion milling apparatus 1 is attached to (inserted into) the observationapparatus (not illustrated). Next, the operator operates the movementmechanism of the cap movable portion 902 to move the cap movable portion902 in an arrow X2 direction to a position where the processing surface603 of the sample 203 can be observed (or to the completely retractedposition of the cap movable portion 902). Then, the operator observesthe processing surface 603 by irradiating the processing surface 603 ofthe sample 203 with the electron beam 602. When observing the processingsurface 603, it is not required to set the tip portion 32 to be in thevertical state as described above.

By providing the cap cover described above at the tip of the side entrytype sample holder 30, it is possible to avoid sample breakage, dirt, orair exposure during transport in the movement between apparatuses (forexample, between the ion milling apparatus and the observationapparatus).

(3) Conclusion

(i) A sample holder (side entry type sample holder) according to thepresent embodiment includes a grip, a sample holder main body extendingfrom the grip, a tip portion which is connected to the sample holdermain body and provided with a sample table for fixing a sample, and amechanism which changes a relative positional relationship of theprocessing surface of the sample fixed to the sample table with anirradiation direction of the ion beam, and causes the tip portion toavoid irradiation with the ion beam during the sample processing.According to this, it is possible to avoid that the tip portion (pivot)of the holder is damaged by being exposed to the ion beam duringprocessing. In addition, since a direction of the processing surface ofthe sample can be changed, it is possible to save troubles of removingthe sample from the holder after being processed with the ion millingapparatus, and attaching the sample again to the holder of theobservation apparatus, the throughput can be improved.

Specifically, the mechanism rotates the tip portion toward a directionopposite to a direction in which the ion source that performsirradiation with the ion beam has been provided, from a state where thetip portion is horizontal to the sample holder main body. The tipportion rotates about a rotation shaft provided at a connecting portionbetween the tip portion and the sample holder main body. It is possibleto prevent the tip portion from being exposed to the ion beam, with sucha simple configuration.

Further specifically, the mechanism includes a first shaft that ishoused inside the sample holder main body, extends in a direction fromthe connecting portion between the tip portion and the sample holder tothe grip, and has a first gear and a second shaft that has the same axisas the rotation shaft of the tip portion. The first shaft has a firstgear and the second shaft has a second gear, respectively. Then, when arotational force for rotating the first shaft is applied around an axisof the first shaft, the rotational force is transmitted to the secondgear via the first gear to rotate the second shaft. Since the secondshaft is attached to the tip portion, the tip portion also rotates inthe same manner, by rotating the second shaft. Since such a simpleconfiguration can be adopted, it is possible to ensure the durability ofthe mechanism which rotates the tip portion.

In a state where the tip portion is horizontal to the sample holder mainbody, the sample table fixes the sample so that the processing surfaceof the sample faces the ion source that performs irradiation with theion beam. On the other hand, in a state where the tip portion has beenrotated to a side opposite to the direction in which the ion source isprovided, the sample table fixes the sample so that the processingsurface becomes horizontal to the irradiation direction of the ion beam.That is, a posture of the tip portion is changed by approximately 90degrees by the mechanism, accordingly, a posture of the sample fixed tothe tip portion is changed by approximately 90 degrees. In this manner,since the position of the processing surface with respect to the ionsource (also for the charged particle beam source (electron source) inthe observation apparatus) can be changed, both the processing andobservation can be performed without removing the sample from the sampleholder.

(ii) The ion milling apparatus according to the present embodimentfurther includes a swing mechanism that rotates the tip portion of thesample holder by predetermined angle clockwise and counterclockwiseabout an axis of the sample holder main body, in addition to having thesample holder described above. Specifically, the swing mechanismincludes a motor, a control unit that controls a rotation of the motor,and a stage side gear that meshes with a gear of the motor and isprovided outside the stage. The stage rotates by a predetermined angleclockwise and counterclockwise about the axis of the sample holderaccording to the rotation of the motor, thereby rotating the sampleholder attached to the stage by the predetermined angle. According tothis, it is possible to prevent the streaks from being formed on theprocessing surface when processing the sample with the ion beam.

(iii) A sample processing method according to the present embodimentincludes: a step of performing predetermined preparing on the sample(cutting the sample or grinding the processing surface to obtain adesired sample size); a step of fixing the sample to a sample tableprovided on the tip portion of the sample holder so that the processingsurface of the sample faces an ion source when inserting the side entrytype sample holder into the sample chamber of the ion milling apparatus(at this time, it is desirable that the shielding plate is placed on anupper face of the sample); a step of inserting the sample holder intothe sample chamber of the ion milling apparatus; a step of causing theprocessing surface of the sample fixed to the sample table to beparallel to an irradiation direction of the ion beam by rotating the tipportion of the sample holder to a side opposite to a direction in whichthe ion source is provided; a step of irradiating the sample with theion beam to process the sample; a step of changing the processingsurface from a state parallel to the irradiation direction of the ionbeam to a state facing the ion source by rotating the tip portion of thesample holder in a direction in which the ion source is provided, afterfinishing the processing of the sample; and a step of extracting thesample holder on which the sample after subjected to the processing isplaced, from the sample chamber. By performing these steps, during thesample processing, the tip portion of the sample holder can be protectedfrom damage caused by the irradiation with the ion beam.

In the step of processing the sample, a swing mechanism, that the ionmilling apparatus has, may rotate the tip portion of the sample holderby predetermined angle clockwise and counterclockwise about an axis ofthe sample holder main body. Accordingly, it is possible to preventstripes from being formed on the processing surface of the sample due tothe irradiation with the ion beam.

(iv) A sample observing method according to the present embodimentincludes: a step of inserting the sample holder (the tip portion and thesample holder main body are in the horizontal state) extracted from thesample chamber of the ion milling apparatus into the observationapparatus while being in a state of attaching the sample to the sampleholder; and a step of observing the processing surface of the sampleusing the observation apparatus. The sample holder used here includes agrip, a sample holder main body extending from the grip, the tip portionwhich is connected to the sample holder main body and provided with thesample table, and a mechanism which rotates the tip portion toward adirection opposite to a direction in which the charged particle beamsource of the observation apparatus is provided from a state where thetip portion is horizontal to the sample holder main body and changes arelative positional relationship between the processing surface of thesample fixed to the sample table and the irradiation direction of thecharged particle beam. In the step of insertion to the observationapparatus and the step of observation, the tip portion is horizontal tothe sample holder main body and the processing surface of the sample isin a state of facing the charged particle beam source of the observationapparatus. Accordingly, in a case where the sample is observed with theobservation apparatus, the tip portion is not rotated by the mechanismof the sample holder. In this manner, since the sample holder extractedfrom the sample chamber of the ion milling apparatus can be insertedinto the observation apparatus as it is (it is not required to removethe sample from the sample table), steps for observation can besimplified and the throughput can be improved. In addition, even in acase where it is determined that the milling processing is insufficient,the sample holder can be extracted from the observation apparatus toinsert into the ion milling apparatus as it is. Therefore, the procedureof processing and observation is simple and usability is extremely good.Further, since it is not required to remove the sample from the sampleholder, it is possible to reduce a concern that the sample is damaged.

REFERENCE SIGNS LIST

-   -   1: Ion milling apparatus    -   10: Sample chamber    -   11: Flare prevention diaphragm    -   20: Stage    -   21: Stage side gear    -   22: Rotation base    -   30: Side entry type sample holder    -   31: Rotation shaft (Sample holder main body)    -   32: Tip portion    -   33: Rotation shaft (Tip portion)    -   34: Grip    -   35: Sample holder main body    -   36: Knob    -   40: Motor    -   41: Motor side gear    -   50: Control unit    -   60: Ion gun    -   202: Shielding plate    -   203: Sample    -   206: Processing surface

1. A sample holder which is inserted in an ion milling apparatus so as to transverse an irradiation locus of an ion beam and is extracted from the ion milling apparatus after a sample processing, the sample holder comprising: a grip; a sample holder main body extending from the grip; a tip portion which is connected to the sample holder main body and provided with a sample table for fixing a sample; and a mechanism which changes a relative positional relationship between a processing surface of the sample fixed to the sample table and an irradiation direction of the ion beam, and causes the tip portion to avoid irradiation with the ion beam during sample processing.
 2. The sample holder according to claim 1, wherein in a state where the tip portion is horizontal to the sample holder main body, the mechanism rotates the tip portion toward a direction opposite to a direction in which an ion source that performs irradiation with the ion beam is provided.
 3. The sample holder according to claim 2, wherein the mechanism rotates the tip portion about a rotation shaft provided at a connecting portion between the tip portion and the sample holder main body.
 4. The sample holder according to claim 3, wherein the mechanism includes a first shaft that is housed inside the sample holder main body, extends in a direction from the connecting portion to the grip, and includes a first gear, and a second shaft that has the same axis as the rotation shaft and includes a second gear, and when a rotational force for rotating the first shaft is applied around an axis of the first shaft, the rotational force is transmitted to the second gear via the first gear to rotate the second shaft.
 5. The sample holder according to claim 2, wherein in a state where the tip portion is horizontal to the sample holder main body, the sample table fixes the sample so that a processing surface of the sample faces the ion source that performs irradiation with the ion beam.
 6. The sample holder according to claim 5, wherein in a state where the tip portion is rotated to a side opposite to the direction in which the ion source is provided, the sample table fixes the sample so that the processing surface becomes parallel to the irradiation direction of the ion beam.
 7. An ion milling apparatus that processes a sample using an ion beam, the apparatus comprising: a sample chamber; an ion source that emits the ion beam and is attached to the sample chamber; a sample holder which is inserted so as to transverse an irradiation locus of the ion beam and is extracted after sample processing; and a stage that holds the inserted sample holder, wherein the sample holder includes a grip, a sample holder main body extending from the grip, a tip portion which is connected to the sample holder main body and provided with a sample table for fixing the sample, and a mechanism which rotates the tip portion toward a direction opposite to a direction in which the ion source that performs irradiation with the ion beam is provided from a state where the tip portion is horizontal to the sample holder main body, changes a relative positional relationship between a processing surface of the sample fixed to the sample table and an irradiation direction of the ion beam, and causes the tip portion to avoid irradiation with the ion beam during the sample processing.
 8. The ion milling apparatus according to claim 7, wherein the mechanism in the sample holder rotates the tip portion about a rotation shaft provided at a connecting portion between the tip portion and the sample holder main body, and the mechanism includes a first shaft that is housed inside the sample holder main body, extends in a direction from the connecting portion to the grip, and includes a first gear, and a second shaft that has the same axis as the rotation shaft and includes a second gear when a rotational force for rotating the first shaft is applied around an axis of the first shaft, the rotational force is transmitted to the second gear via the first gear to rotate the second shaft.
 9. The ion milling apparatus according to claim 7, further comprising: a swing mechanism that rotates the tip portion of the sample holder by a predetermined angle clockwise and counterclockwise about an axis of the sample holder main body.
 10. The ion milling apparatus according to claim 9, wherein the swing mechanism includes a motor, a control unit that controls a rotation of the motor, and a stage side gear that meshes with a gear of the motor and is provided outside the stage, when the stage is rotated by a predetermined angle clockwise and counterclockwise about the axis of the sample holder according to the rotation of the motor, the sample holder attached to the stage is rotated by the predetermined angle.
 11. The ion milling apparatus according to claim 7, further comprising: a diaphragm that defines a range to be irradiated with the ion beam; and a shielding plate that covers a portion of the sample other than a portion to be scrapped by the ion beam.
 12. A sample processing method of processing a sample with an ion beam, the method comprising steps of: performing predetermined preparing on the sample; fixing the sample to a sample table provided on a tip portion of a sample holder so that a processing surface of the sample faces an ion source that emits the ion beam when inserting the sample holder into a sample chamber of an ion milling apparatus; inserting the sample holder into the sample chamber of the ion milling apparatus; causing the processing surface of the sample fixed to the sample table to be parallel to an irradiation direction of the ion beam by rotating the tip portion of the sample holder to a side opposite to a direction in which the ion source is provided; irradiating the sample with the ion beam to process the sample; changing the processing surface from a state parallel to the irradiation direction of the ion beam to a state facing the ion source by rotating the tip portion of the sample holder in a direction in which the ion source is provided, after finishing the processing of the sample; and extracting the sample holder on which the sample after subjected to the processing is placed, from the sample chamber, wherein the sample holder includes a grip, a sample holder main body extending from the grip, the tip portion which is connected to the sample holder main body and provided with the sample table, and a mechanism which, in a state where the tip portion is horizontal to the sample holder main body, rotates the tip portion toward a direction opposite to the direction in which the ion source that performs irradiation with the ion beam is provided, changes a relative positional relationship between the processing surface of the sample fixed to the sample table and the irradiation direction of the ion beam, and causes the tip portion to avoid irradiation with the ion beam during the sample processing.
 13. The method according to claim 12, wherein in the step of processing the sample, a swing mechanism, which the ion milling apparatus includes, rotates the tip portion of the sample holder by a predetermined angle clockwise and counterclockwise about an axis of the sample holder main body.
 14. A sample observing method of observing a sample processed with an ion milling apparatus, using an observation apparatus, the method comprising steps of: inserting a sample holder extracted from a sample chamber of the ion milling apparatus into the observation apparatus while the sample is attached to the sample holder; and observing a processing surface of the sample using the observation apparatus, wherein the sample holder includes a grip, a sample holder main body extending from the grip, a tip portion which is connected to the sample holder main body and provided with a sample table, and a mechanism which, in a state where the tip portion is horizontal to the sample holder main body, rotates the tip portion toward a direction opposite to a direction in which a charged particle beam source of the observation apparatus is provided and changes a relative positional relationship between the processing surface of the sample fixed to the sample table and an irradiation direction of a charged particle beam, and in the step of insertion into the observation apparatus and the step of observation, the tip portion is horizontal to the sample holder main body and the processing surface of the sample is in a state of facing the charged particle beam source of the observation apparatus.
 15. A sample processing and observing method of processing a sample with an ion milling apparatus and observing the processed sample with an observation apparatus, the method comprising steps of: performing predetermined preparing on the sample; fixing the sample to a sample table provided on a tip portion of a sample holder so that a processing surface of the sample faces an ion source that emits an ion beam when inserting the sample holder into a sample chamber of the ion milling apparatus; inserting the sample holder into the sample chamber of the ion milling apparatus; causing the processing surface of the sample fixed to the sample table to be parallel to an irradiation direction of the ion beam by rotating the tip portion of the sample holder to a side opposite to a direction in which the ion source is provided; irradiating the sample with the ion beam to process the sample; changing the processing surface from a state parallel to the irradiation direction of the ion beam to a state facing the ion source by rotating the tip portion of the sample holder in the direction in which the ion source is provided, after finishing the processing of the sample; extracting the sample holder on which the sample after subjected to the processing is placed, from the sample chamber; inserting the sample holder extracted from the sample chamber of the ion milling apparatus into the observation apparatus while the sample is attached to the sample holder; and observing the processing surface of the sample with the observation apparatus, wherein the sample holder includes a grip, a sample holder main body extending from the grip, the tip portion which is connected to the sample holder main body and provided with the sample table, and a mechanism which rotates the tip portion toward a direction opposite to the direction in which the ion source that performs irradiation with the ion beam is provided from a state where the tip portion is horizontal to the sample holder main body, and changes a relative positional relationship between the processing surface of the sample fixed to the sample table and the irradiation direction of the ion beam, and in the step of insertion to the observation apparatus and the step of observation, the tip portion is horizontal to the sample holder main body and the processing surface of the sample is in a state of facing a charged particle beam source of the observation apparatus. 